Surgical tubing



nited rates 'Patent @fihce 3,034,509 Patented May 15, 1962 3,034,509 SURGICAL TUBING Richard K. Bernstein, Bronx, and George Gods, New York, N.Y., assignors to Clay-Adams, Inc., New York, N.Y., a corporation of New York No Drawing. Filed Sept. 6, 1960, Ser. No. 53,890 6 Claims. (Cl. 128348) This invention relates to surgical or medical tubing, and more particularly, concerns tubing or cannula formed of polyethylene.

While polyethylene tubing has been extensively used for surgical and medical purposes, it has been found that such tubin may be modified by specific formulation of the polyethylene to effect substantial improvement in a number of its properties particularly pertinent to its surgical or medical usage.

Accordingly, one object of this invention is to provide an improved tubing or cannula formed of a modified polyethylene resin, which in use retards blood coagulation over extended periods of time, thereby minimizing the formation of obstructions in the tubing due to coagulated blood.

Another object of this invention is to provide an improved polyethylene tubing for surgical or medical usage, which when in contact with tissue over extended periods of time, does not give rise to toxic reactions or irritation of the tissue.

A further object of this invention is to provide an improved cannula formed of modified polyethylene resin, which displays increased inertness with respect to blood, thereby materially decreasing deleterious effects on the blood as an incident to the surgical or medical usage of such cannula.

Still another object of this invention is to provide an improved surgical or medical tubing or cannula which permits a maximum rate of liquid flow therethrough, thereby facilitating the transmission of nutrient solutions, blood or other liquid media being transported by way of such tubing or cannula.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

In accordance with the instant invention, polyethylene resin has admixed therewith a suitable amount of organosilicon polymers, particularly, polymers in the form of silicone oils or liquids. The mixture is extruded through suitable extruding means to form tubing of a selected inner and outer diameter.

The silicone polymer is well distributed through the Walls of the tubing and such tubing when used in connection with surgical or medical procedures, has been found to be of uniform character in respect to a number of enhanced properties which make the same particularly suitable for intravenous therapy, transfusions, as well as a variety of other surgical or medical procedures.

Thus, the polyethylene is admixed with from about 0.15 to about 1.00% by weight of a silicone oil sold under the designation of 200 Fluids by Dow Corning Corp. or G E Silicone Oils by General Electric Company. Such silicone derivatives are essentially dimethyl derivatives of the polysiloxanes and may have viscosities ranging from 0.65 to over 1,000,000 centistokes at 25 C. However, for the particular purpose herein, oils having viscosities of from about 250 to about 450 centistokes at 25 C. are preferred.

Tubing was formed from polyethylene resin havmg a content of 0.5% by weight of silicone oil, by extrusion of the resin-oil mixture. The result-ant tubing was found to have a high degree of inertness with respect to blood and after implant over extended periods of time, the tissues were found to be free of toxic effects or irritation. Also, the tubing had excellent flow characteristics for blood and nutrient solutions and retarded blood coagulation over long periods of usage.

Tubing formed from the mixture of polyethylene and silicone oil, was produced in a wide range of sizes vary ing from .011 ID. x .024" OD. to .500" ID. x .560 OD. For the smaller sizes of tubing, the silicone oil content may be of the order of from about 0.35 to about 0.40% by weight. For the larger sizes of tubing, the silicone oil content may be increased to from about 0.5 to about 0.6% by weight.

It has been found that the substantially uniform distribution of the polymethylsiloxane through the polyethylene forming the tubing Wall is responsible for the optimum properties exhibited in surgical and medical usage, including inertness, freedom from toxic reactions and irritation, retarding blood coagulation and the like. Furthermore such properties are maintained through the normal life of the tubing, apparently by reason of the slight migration of the polymethylsiloxane through the tubing wall to the inner and outer surfaces thereof.

As various changes might be made in the embodiments of the invention disclosed herein without departing from the spirit thereof, it is understood that all matter herein described shall be deemed illustrative and not limiting except as set forth in the appended claims.

What is claimed is:

1. A surgical tubing for contact with human tissue or blood comprising polyethylene and a polyorganosiloxane distributed homogeneously and uniformly throughout the thickness of the tubing wall in amounts of from about 0.15 to about 1.00% by weight, wherein said polyorganosiloxane tends to migrate to the surfaces of said tubing.

2. A surgical tubing for contact with human tissue or blood comprising an extruded body of polyethylene and polymethylsiloxane, said polymet-hylsiloxane being present in amounts of from about 0.4 to about 0.5% by weight and homogeneously and uniformly distributed throughout the thickness of the tubing wall.

3. A surgical tubing for contact with human tissue or blood comprising polyethylene and about 0.5 by weight of a silicone oil distributed homogeneously and uniformly through the wall of the tubing for migration to the wall surfaces of said tubing.

4. A surgical tubing as in claim 3 wherein said silicone oil is polymethylsiloxane.

5. A surgical tubing as in claim 4 wherein said polymethylsilox-ane has a viscosity of from about 250 to about 450 centistokes at 25 C.

6. A surgical tubing for contact with human tissue or blood, comprising a tubing of extruded polyethylene and about 0.5 by weight of liquid polydimethylsiloxane having a viscosity of about 350 centistokes at 25 C., said polydimethylsiloxane being homogeneously and uniformly distributed through the wall of said tubing.

References Cited in the file of this patent McGregor: Silicones in Medicine aed Surgery, received in R0. Lib., June 20, 1957, pages 19-20 required, 167$ilicone. 

